1. Field of the Invention
The present invention relates to a communication apparatus connected to a plurality of lines capable of transmitting/receiving data via the plurality of lines, and a method for controlling the communication apparatus.
2. Description of the Related Art
Multifunction peripherals having functions of copying, printing, scanning, and a facsimile have been widely used. Recently, multifunction peripherals having a much wider variety of functions with reduced footprints and lower power consumption have been proposed.
Many conventional multifunction peripherals include a facsimile function that supports only two lines. Recent demand has been for a facsimile function that can accommodate more then two lines.
The demand has arisen because a multifunction peripheral having a connection with a plurality of lines allows an integration of devices with a reduced footprint. In addition, efficient multi-address transmission can be performed using a plurality of lines. The multi-address transmission refers to transmission of any data to a plurality of addresses.
Accordingly, if one peripheral accommodates a plurality of lines, data can be simultaneously transmitted to a plurality of addresses via the plurality of lines. Thus, transmission efficiency can be increased and the multi-address transmission can be performed in a shorter time. To satisfy such a demand for a multifunction peripheral that can accommodate multi-lines, a multifunction peripheral having a larger number of communication channels has been proposed.
However, when data is transmitted via a plurality of lines at the same time, a load on a control unit (main controller) for controlling devices increases and software processing cannot respond to the increase, resulting in, among other things, interruption of communication. Japanese Patent Application Laid-Open No. 2004-48159 addresses this by implementing a technique for distributing the load on the control unit via a software program.
According to this technique, a special controller (sub controller) for a facsimile (communication) unit is provided in addition to a controller (main controller) of a multifunction peripheral, and the sub controller executes communication processing. Such load distribution processing enables increase of a number of lines and real-time communication processing.